The compound 10-[3-(4-hydroxyethyl-1-piperazinyl)propylidene]-2-trifluroromethyl thiaxanthene has in the recent years, in the form of a mixture of the cis-trans isomers, proved outstanding as a neuroleptic drug in the treatment of psychotic disorders, mostly schizophrenic patients.
The compound, which in the following is called flupenthixol (pINN) for short, is effective in small doses and is preferably used in the form of acid addition salts such as the dihydrochloride in oral unit dosage forms. The daily dose normally is in the range of 1 - 3 mg three times a day. When patients are discharged from hospital on a maintenence dosis it has often been a problem to have the patients take the tablets, and the result has been a high degree of recurrences.
Recently it has been suggested to administer the most potent isomer of flupenthixol, the alpha-form, in the form of the decanoic acid ester, as oily solution for injection, and it has been shown that such solutions have a prolonged effect as compared with the unesterified alpha-isomer.